JP6855921B2 - Evaluation method for 3-point bending of evaluation members - Google Patents

Description

The present invention relates to a three-point bending evaluation method for an evaluation member.

Conventionally, a high-strength and lightweight vehicle body structure has been required in order to achieve both collision performance and fuel efficiency of an automobile, and studies on increasing the tension and thinning of the vehicle body structural parts are being continuously conducted. For example, for a door impact beam, which is a component that suppresses deformation of the passenger compartment during a side collision, collision evaluation using a full vehicle is ideal for evaluating the consideration of increasing tension and thinning of this component, but man-hours and costs There are many disadvantages in terms of, and it is not easy. Therefore, as described in Patent Document 1, a method of reproducing a bending moment, a tensile load, or the like by using an evaluation member has been proposed. As another method, there is also a simple three-point bending evaluation method using only evaluation parts.

Japanese Unexamined Patent Publication No. 2015-108585

However, in the conventional three-point bending evaluation method, there is a frictional effect on the restraint portion. In addition, since the influence of the peripheral parts to be joined is not taken into consideration, there is room for improvement in the application evaluation.

The present invention is an invention made in such a background, and an object of the present invention is to simulate an environment generated for a part corresponding to a single evaluation member during a full vehicle collision test, and to handle bending and tensile loads received at the time of collision. It is an object of the present invention to provide a tensile three-point bending evaluation method capable of accurately reproducing the influence in the evaluation member.

The following means will be adopted to solve the above problems. That is, it is a three-point bending evaluation method of the evaluation member, which is characterized in that the tensile load applied to both ends of the evaluation member is controlled according to the stroke of the indenter.

Further, it is preferable that the relationship between the indenter stroke and the tensile load is obtained in advance by simulation, and the actuator that applies the tensile load to the evaluation member is controlled based on the obtained result.

According to the present invention, a tensile three-point bending evaluation method capable of simulating the environment generated for a part corresponding to a single evaluation member during a full vehicle collision test and accurately reproducing the effects of bending and tensile load on the evaluation member during a collision. Can be provided.

It is a figure showing both the state before deforming the evaluation member fixed to the evaluation jig, and the state after deforming by the movement of an indenter. It is the schematic which showed how the force is applied when the evaluation member is deformed. It is a figure which shows the state which the pole collided with the side surface of a vehicle. It is the figure which showed the state of the deformation of a door impact beam by a collision with a pole. It is a figure which showed the state of the deformation around a door in the event shown by FIG. It is a figure showing a state in which the evaluation member was bent by simulating the deformation of the member shown in FIG. To. In the figure showing the relationship between the stroke amount of the indenter and the load applied to the actuator. is there. It is a figure which showed the relationship between the stroke amount of an indenter and the load applied to an indenter.

Hereinafter, embodiments of the invention will be described. In the evaluation method in the present embodiment, the evaluation member 1 is bent at three points. At this time, the tensile load applied to both ends of the evaluation member 1 is controlled according to the stroke of the indenter 33. For this reason, a tensile three-point bending evaluation method that can accurately reproduce the effects of bending and tensile load on the evaluation member 1 during a full vehicle collision test by simulating the environment that occurs for a part corresponding to the evaluation member 1 alone. Can be provided.

As shown in FIG. 1, in the present embodiment, an evaluation jig is used to enable the evaluation member 1 to be evaluated. The evaluation jig of the present embodiment is provided with two mounting arms 31 connected to the evaluation member 1. Each of these mounting arms 31 is arranged on both end sides of the evaluation member 1. Further, the mounting arm 31 is rotatably connected to a shaft fixed to the support base 35. More specifically, by attaching a rotatable bearing 34 to this shaft, the attachment arm 31 can be rotated. Therefore, when the evaluation member 1 receives a pressing force from the indenter 33, the mounting arm 31 can rotate. Further, by providing the bearing 34, the frictional force that the mounting arm 31 receives when rotating is suppressed. The mounting arm 31 is used to simulate the deformation locus.

In the present embodiment, a tensile load is applied so that the evaluation member 1 resists the force for rotating the mounting arm 31. A tension chain 36 is connected to the mounting arm 31 in order to generate this tensile load, and an actuator 32 is connected to the tension chain 36. By adjusting the actuator 32, the tensile load can be adjusted. The mounting arm 31 of the present embodiment has an evaluation member 1 connected to one side, and a tension chain 36 that transmits a tensile load to the evaluation member 1 is connected to the other side.

As can be seen from FIGS. 1 and 2, when the compressive force F1 is applied to the evaluation member 1 by the indenter 33, the actuator 32 located outside the mounting arm 31 is the tension chain 36 and the mounting arm. A tensile load F2 is applied to the evaluation member 1 via 31. At this time, the actuator 32 is controlled to provide an appropriate tensile load. More specifically, by using CAE (computer aided engineering) or the like, the relationship between the stroke of the indenter 33 and the tensile load is obtained in advance by simulation, and the air cylinder which is the actuator 32 is controlled based on the result. At this time, by controlling the tensile load applied to the evaluation member 1 based on the CAE according to the stroke of the indenter 33, it is possible to evaluate the single unit fracture in the same environment as the collision evaluation in a full vehicle. ..

Here, the relationship with the actual vehicle test will be described. In the actual vehicle test, a test was conducted assuming that the pole collided with the side surface of the vehicle. As a result, as shown in FIG. 3, the vehicle was deformed. A door impact beam that functions as an energy absorbing member is arranged on the side of the vehicle, and the door impact beam is deformed as shown in FIGS. 4 and 5 due to a collision with a pole. This door impact beam was deformed while receiving both a compressive bending load from the pole and a tensile load from the door inner. In the present invention, the tensile load corresponding to the force from the door inner can be reproduced by the actuator 32.

In the evaluation jig of the present invention, for example, the "stroke of the indenter 33" and the "actuator 32" that deform the evaluation member 1 by obtaining the relationship between the "vehicle approach amount" and the "tensile load from the door inner" from the simulation. the load "results it can be seen that may be set as shown in FIG. Therefore, by controlling the actuator 32 according to the approach amount of the indenter 33 so as to behave as shown in FIG. 7 , the timings of both loads are matched, and the environment is similar to that of a collision in a full vehicle. It is possible to evaluate the destruction of a single unit.

FIG. 6 shows a change in the evaluation member 1 when the same phenomenon as the deformation of the door impact beam is reproduced by using the evaluation method of the present invention. FIG. 8 shows a graph showing the relationship between the result of the actual vehicle test and the stroke of the indenter 33 and the load provided by the indenter 33 when the test method of the present invention is used. It can be seen that it can produce results similar to the test.

As described above, according to the present invention, it is possible to set an environment similar to that of a full vehicle collision test for a single evaluation member 1 and perform fracture evaluation without being affected by the friction of the mounting portion, so that the evaluation member 1 can be evaluated at the time of collision. The effects of bending and tensile loads can be accurately reproduced.

The present invention is not limited to the above embodiments, and it goes without saying that the present invention can be applied without departing from the spirit of the present invention.

Claims (1)

This is a three-point bending evaluation method for the evaluation member. In order to control the tensile load applied to both ends of the evaluation member according to the stroke of the indenter, the relationship between the stroke of the indenter and the tensile load is obtained by simulation in advance. A three-point bending evaluation method for an evaluation member, which comprises controlling an actuator that applies a tensile load to the evaluation member based on the results.

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